An epoxy resin composition for motor rotor encapsulation

Abstract

This invention discloses an epoxy resin composition for motor rotor encapsulation, comprising: a multifunctional epoxy resin, a multifunctional phenolic resin, an accelerator, an inorganic filler, a quinoline chelating agent, an antioxidant, and other additives. The combination of the multifunctional epoxy resin and the multifunctional phenolic resin achieves a high crosslinking density, thus meeting the glass transition temperature requirements for high-temperature applications. The use of a special quinoline chelating agent as an adhesion promoter significantly improves the room temperature and high temperature adhesion of the epoxy resin composition, as well as its aging thermal stability. Furthermore, the introduction of the antioxidant greatly improves the stability of the material's mechanical and adhesive properties under long-term high-temperature operating conditions, meeting the requirements of long-term high-speed motor operation.

Description

Technical Field

[0001] This invention relates to the field of materials for motor rotor packaging, and in particular to an epoxy resin composition for motor rotor packaging. Background Technology

[0002] The choice of motor rotor encapsulation material depends on the type of motor, speed, power density, and specific operating conditions. Currently, the main types of materials include protective sleeves, such as carbon fiber composites, which can eliminate eddy current losses caused by metal sheaths and greatly improve motor efficiency. High-strength alloy metals, while meeting mechanical strength requirements, can generate eddy current losses and heat in high-speed magnetic fields. Encapsulation materials used for potting or bonding include epoxy resin and modified polymer composites, which are used to fill the voids inside the rotor, fix the magnets and core, and provide insulation, heat conduction, and vibration damping.

[0003] Epoxy resin is a thermosetting polymer that, after curing, adheres to metals, glass, and concrete while maintaining its tensile, compressive, and flexural strength. It can withstand mechanical stress, vibration, and impact without easily breaking. Epoxy resin can be used as an adhesive to achieve high-strength bonding between metals, non-metals, and plastics. Particularly in the field of motor encapsulation, the high glass transition temperature of epoxy resin allows it to withstand the large amount of heat generated by the motor rotor during high-speed operation. Furthermore, it can form a dense insulating barrier between rotor components, preventing high-voltage breakdown and current leakage, or effectively isolating magnets from direct contact with the external environment, significantly reducing eddy current losses, thereby improving the overall energy efficiency of the motor.

[0004] Current motor rotor encapsulation materials, such as the patent application with patent number CN109082077A, disclose motor rotor encapsulation materials that use epoxy resin as a base material to prepare fluorinated resin, weather-resistant agents, and titanate coupling agents. Although these traditional motor rotor encapsulation materials use epoxy resin as a base material to prepare epoxy resin materials that can improve weather resistance at slightly higher temperatures, the adhesion of these traditional motor rotor encapsulation materials decreases as the temperature rises due to the centrifugal force exerted by the motor rotor during high-speed operation. This results in the problem that the magnets are prone to detachment when the operating temperature increases. Summary of the Invention

[0005] The purpose of this invention is to address the problem that existing motor rotor encapsulation materials suffer from decreased adhesion at higher temperatures, leading to easy detachment of magnets at increased operating temperatures, by providing an epoxy resin composition for motor rotor encapsulation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An epoxy resin composition for encapsulating an electric motor rotor comprises the following raw materials in parts by weight: 9.05-20% epoxy resin, 5-20% phenolic resin, 0.15%-3% accelerator, 0.5%-3% quinoline chelating agent, 80%-90% inorganic filler, 0.4%-3% antioxidant, and 0.2%-4.55% additives.

[0008] The epoxy resin composition for motor rotor encapsulation described in this invention improves the combination of epoxy resin and phenolic resin as resin raw materials. The epoxy resin optimizes the brittleness of the phenolic resin, improving the fracture toughness and impact resistance of the composition. The phenolic resin addresses the insufficient heat resistance of the epoxy resin, giving the composition extremely high heat resistance, rigidity, and resistance to crack initiation and propagation. This, in turn, increases the crosslinking density to raise the glass transition temperature of the material, meeting the high-temperature weather resistance requirements of the epoxy resin composition for motor rotor encapsulation. Furthermore, by incorporating a quinoline chelating agent as a bonding promoter, replacing the traditional coupling agent, the adhesiveness and aging thermal stability of the epoxy resin composition for motor rotor encapsulation are significantly improved at both room temperature and high temperature. Even in high-temperature environments above 200°C for motor rotors, it can maintain strong adhesion to prevent magnet detachment, thereby improving the quality and reliability of motor rotor encapsulation.

[0009] Preferably, the epoxy resin composition for motor rotor encapsulation of the present invention comprises a multifunctional epoxy resin and a multifunctional phenolic resin.

[0010] As a preferred embodiment of the present invention, by optimizing the combination of multifunctional epoxy resin and multifunctional phenolic resin as raw materials, an extremely dense three-dimensional network structure can be formed after curing, achieving better heat resistance, solvent resistance and dimensional stability, and its glass transition temperature and thermal degradation temperature are further significantly higher; and in combination with multifunctional epoxy resin, the deficiency of reducing the brittleness of multifunctional phenolic resin is optimized, and a high heat-resistant skeleton and high activity and adhesion performance are obtained after encapsulation and curing.

[0011] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the molecular structure of the multifunctional epoxy resin is one or a combination of two of molecular formula one and molecular formula two.

[0012] Molecular Formula 1:

[0013] ;

[0014] Molecular Formula 2:

[0015] .

[0016] As a preferred embodiment of the present invention, by selecting the multifunctional epoxy resin with the above-mentioned molecular formula, a high degree of compatibility with phenolic resin is achieved, thereby improving the mechanical properties and bonding stability of the epoxy composition under long-term high-temperature working conditions, and further enhancing the robustness of the rotor fixed connection during long-term high-speed operation of the motor.

[0017] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the molecular structure of the multifunctional phenolic resin is one or more combinations of molecular formula III, molecular formula IV or molecular formula V.

[0018] Molecular Formula 3:

[0019] ;

[0020] Molecular Formula 4:

[0021] ;

[0022] Molecular Formula 5:

[0023] .

[0024] As a preferred embodiment of the present invention, by setting the above-mentioned multifunctional phenolic resin with molecular formulas of four or five and their mixtures, the toughness, mechanical strength and adhesion to metal substrates of the composition are further improved while maintaining the original heat resistance.

[0025] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the quinoline chelating agent is one or more of amino-substituted quinoline alcohol, carboxyl-substituted quinoline alcohol, hydroxyquinoline ketone, sulfonic acid-substituted quinoline alcohol, and Schiff base quinoline.

[0026] As a preferred embodiment of the present invention, by using quinoline chelating agents, the room temperature and high temperature adhesion and aging thermal stability of the epoxy resin composition are significantly improved. Combined with the effect of antioxidants, the mechanical properties and adhesion stability of the composition material under long-term high-temperature working environment are further improved.

[0027] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the quinoline chelating agent is an amino-substituted quinoline alcohol.

[0028] As a preferred embodiment of the present invention, based on achieving adhesive performance, the active hydrogen on the amino group directly undergoes a ring-opening addition reaction with the epoxy group of the epoxy resin, embedding into the three-dimensional network structure of the epoxy resin and becoming part of the cured product, thereby significantly improving the crosslinking density of the material; the amino polar group can form a very strong physical adsorption or chemical bond with the surface of the metal substrate, significantly improving the mechanical strength and heat resistance, further optimizing the high-temperature adhesion and post-heat aging adhesion of the oxidized resin composition, increasing the adhesion strength after high temperature to 72%, and further improving the high-temperature thermal adhesion of the composition.

[0029] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the quinoline chelating agent is composed of 0.5%-0.8% quinoline chelating agent.

[0030] As a preferred embodiment of the present invention, by setting the mass ratio range of the quinoline chelating agent components, the crosslinking density and rigidity of the curing system of the composition are enhanced, the curing speed of the epoxy resin composition is more precisely controlled, and the toughness is taken into account to enhance the impact resistance to the centrifugal force of the motor rotor rotation, thereby further reducing the risk of microcracks appearing in the motor rotor after long-term use.

[0031] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the accelerator is one or more selected from organophosphorus compounds, imidazole compounds, tertiary amine compounds, and tertiary amine derivatives.

[0032] As a preferred embodiment of the present invention, the use of the above-mentioned accelerator further improves the heat resistance and mechanical properties of the motor rotor at higher temperatures.

[0033] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the accelerator is one or more of triphenylphosphine, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1,8-diazabicyclo, and undecene-7 (DBU).

[0034] As a preferred embodiment of the present invention, by accelerating the curing reaction rate, reducing the curing temperature, and shortening the curing time, and by leveraging the promoting effect of the curing agent, a smaller amount is used and the activity is higher, enabling rapid and complete curing, thereby further improving the curing performance and efficiency of the epoxy resin composition.

[0035] Preferably, in the epoxy resin composition for motor rotor encapsulation of the present invention, the inorganic filler is one or more of crystalline silica, molten silica, spherical silica, metal oxide, and metal nitride.

[0036] As a preferred embodiment of the present invention, the inorganic filler can reduce costs, improve physical and mechanical properties, and endow the material with specific functionality. It has higher thermal conductivity, further optimizes the thermal interface material of the epoxy resin composition, rapidly dissipates heat to protect electronic components, further improves the overall thermal conductivity, reduces the coefficient of thermal expansion, and achieves the best balance between performance and cost.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. The high glass transition temperature can meet the motor operation requirements under high-temperature working conditions;

[0039] 2. Extremely high magnet bonding strength, which can meet the requirements of high-speed motor operation;

[0040] 3. Maintains high bonding strength and mechanical strength under high temperature conditions to meet the long-term working requirements of the motor. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the motor rotor structure encapsulated with the epoxy resin composition of the present invention.

[0042] 1-Rotor metal part; 2-Epoxy resin composition. Detailed Implementation

[0043] The present invention will now be described in detail with reference to the accompanying drawings.

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0045] Example 1:

[0046] This embodiment discloses an epoxy resin composition for motor rotor encapsulation, comprising the following raw materials in parts by weight: 9.05-20% epoxy resin, 5-20% phenolic resin, 0.15%-3% accelerator, 0.5%-3% quinoline chelating agent, 80%-90% inorganic filler, 0.4%-3% antioxidant, and 0.2%-4.55% additives.

[0047] The quinoline chelating agents described in this invention are understood as organic compounds containing a quinoline ring, capable of chelating transition metal ions such as copper, iron, and zinc, thereby avoiding or reducing the catalytic oxidation reaction of free metal ions and achieving heat resistance and aging resistance. For example, octa-aminoquinoline is used as a chelating agent. In this embodiment, preferably, the quinoline chelating agent is one or more of amino-substituted quinoline alcohols, carboxyl-substituted quinoline alcohols, hydroxyquinoline ketones, sulfonic acid-substituted quinoline alcohols, and Schiff base quinolines. More specifically, the quinoline chelating agent used in this embodiment is an amino-substituted quinoline alcohol. In this embodiment, preferably, the composition of the quinoline chelating agent is 0.5%-0.8%. More specifically, referring to Table 1, 0.5% of octa-aminoquinoline is used as a chelating agent in this embodiment.

[0048] As shown in Table 2, compared to Comparative Example 2, the resin system with a lower glass transition temperature has poorer high-temperature adhesion. Without quinoline chelating agents as adhesion promoters, the adhesion retention rate of the resin composition after thermal aging is also significantly reduced. As shown in Table 1, this embodiment uses quinoline chelating agent raw materials as adhesion promoters, which significantly improves the room temperature and high temperature adhesion and aging thermal stability of the epoxy resin composition.

[0049] Preferably, in this embodiment, the epoxy resin is a multifunctional epoxy resin; the phenolic resin is a multifunctional phenolic resin. Referring to Tables 1 and 2, compared to Comparative Example 1 using o-cresol epoxy resin and linear phenolic resin, or compared to Comparative Example 2 using a combination of multifunctional epoxy resin and linear phenolic resin, the glass transition temperature of this invention, through the combination of multifunctional epoxy resin and multifunctional phenolic resin, reaches above 210°C, which is significantly higher than the glass transition temperature of the oxide resin compositions of Comparative Example 1 and Comparative Example 2.

[0050] The multifunctional epoxy resin described in this invention is understood as a polymer containing two or more crosslinkable epoxy groups per molecule on average. In this embodiment, preferably, the molecular structure of the multifunctional epoxy resin is one or a combination of two of the molecular formulas 1 and 2.

[0051] Molecular Formula 1:

[0052] ;

[0053] Molecular Formula 2:

[0054] .

[0055] In this preferred embodiment, the molecular structure of the multifunctional phenolic resin is one or more combinations of molecular formula III, molecular formula IV, or molecular formula V.

[0056] Molecular Formula 3:

[0057] ;

[0058] Molecular Formula 4:

[0059] ;

[0060] Molecular Formula 5:

[0061] .

[0062] It should be noted that the accelerator of the present invention can accelerate the curing reaction, reduce the reaction temperature, improve the final performance, and reduce the amount of main agent used. In this embodiment, the accelerator is preferably one or more of organophosphorus compounds, imidazole compounds, tertiary amine compounds, and tertiary amine derivatives. More specifically, in this embodiment, the accelerator is preferably one or more of triphenylphosphine, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1,8-diazabicyclo, and undecene-7 (DBU).

[0063] In this preferred embodiment, the inorganic filler is one or more of crystalline silicon dioxide, molten silicon dioxide, spherical silicon dioxide, metal oxides, and metal nitrides.

[0064] The additives described in this invention are understood as additives for fine-tuning and optimizing combinations, such as colorants, release agents, or flame retardants. In this embodiment, the additives are preferably one or more of flame retardants, release agents, coupling agents, colorants, stress absorbers, and ion traps. More specifically, the antioxidants may include hindered phenolic antioxidants and sulfur-containing auxiliary antioxidants.

[0065] The additives described in this invention may include one or more of the following: flame retardants, release agents, coupling agents, colorants, stress absorbers, and ion scavengers; more specifically, flame retardants may include zinc borate, a product of Suzhou Haihua Risheng; release agents may include palm wax; coupling agents may include γ-glycidoxypropyltrimethoxysilane; colorants may include carbon black; stress absorbers may include liquid-state carboxyl-terminated nitrile butadiene rubber; and ion scavengers may include hydrotalcite.

[0066] Table 1: Raw material composition ratios of various embodiments and comparative examples of the present invention

[0067] raw material Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Multifunctional epoxy resin 9.25 9.05 9.25 9.25 8.95 9.25 o-cresol epoxy resin 9.5 Multifunctional phenolic resin 5.15 5 5.15 5.15 5.15 Linear phenolic resin 4.85 5.4 Accelerator 0.15 0.2 0.15 0.15 0.2 0.2 0.15 Inorganic packing 80 80 80 80 80 80 80 8-Aminoquinoline 0.5 0.8 0.5 8-Hydroxyquinoline-pentasulfonic acid 0.5 8-hydroxyquinoline 0.5 Tri-amino-1,2,4-triazole 0.5 0.5 Hindered phenolic antioxidants 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Sulfur-containing auxiliary antioxidants 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Flame retardant 3 3 3 3 3 3 3 Release agent 0.3 0.3 0.3 0.3 0.3 0.3 0.3 Coupling agent 0.35 0.35 0.35 0.35 0.35 0.35 0.35 Colorant 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Stress absorber 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Ion scavengers 0.2 0.2 0.2 0.2 0.2 0.2 0.2

[0068] Example 2:

[0069] Compared with Example 1, this example discloses an epoxy resin composition for motor rotor encapsulation, comprising the following raw materials in parts by weight: 9.05% multifunctional epoxy resin, 5% multifunctional phenolic resin, 0.2% accelerator, 0.8% octa-aminoquinoline, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives, with other conditions and components being the same as in Example 1.

[0070] Example 3:

[0071] Compared with Example 1, this example discloses an epoxy resin composition for motor rotor encapsulation, comprising the following raw materials in parts by weight: 9.25% multifunctional epoxy resin, 5.15% multifunctional phenolic resin, 0.15% accelerator, 0.5% octa-hydroxyquinoline-penta-sulfonic acid, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives, with other conditions and components being the same as in Example 1.

[0072] Example 4:

[0073] Compared to Example 1, this example discloses an epoxy resin composition for motor rotor encapsulation, comprising the following raw materials by weight: 9.25% multifunctional epoxy resin, 5.15% multifunctional phenolic resin, 0.15% accelerator, 0.5% octa-aminoquinoline, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives. Other conditions and components are the same as in Example 1. The multifunctional phenolic resin described in this example can be a combination of two types: 3.65% MEH-7500 from Meiwa Chemical and 1.5% HE910-20 from AirWater.

[0074] It should be noted that the epoxy composition 1 of the present invention contains the raw materials of the aforementioned components. In use, other conventional raw materials can also be added to achieve curing and encapsulation of the rotor metal part 2 of the motor rotor. Specifically, for example... Figure 1 The diagram shows a schematic of the motor rotor structure after curing, where the epoxy resin composition 1 of the present invention is used to encapsulate the motor rotor. After curing, the epoxy resin composition 1 of the present invention encapsulates the rotor metal part 2 to form the motor rotor structure. To test the performance of the epoxy resin composition 1 of the present invention, samples were prepared using epoxy resin compositions 1 from various embodiments and comparative examples of the present invention. The preparation steps are as follows: Using a low-pressure transfer molding machine, under the conditions of mold temperature of 175°C, injection pressure of 60 bar, and curing time of 110 s, the obtained epoxy molding compound was molded on the surface of a sample. A magnetic steel sheet was used to simulate the rotor material in the sample. The sample was placed in a hot air circulating oven and cured at 175°C for 6 h + 15 min, and then cooled to room temperature in a desiccator to obtain the sample.

[0075] The samples were then subjected to performance tests including adhesion strength, high temperature resistance, and glass transition temperature. The adhesion strength test conditions were as follows: using a multi-functional micro-solder joint strength tester, the range was 200 kg for room temperature testing and 50 kg for high temperature testing; the test speed was set to 400 μm / s, the maximum load to 220 kg, the overshoot to 100 μm, the test height to 500 μm, and the descent speed to 1200 μm / s. The high temperature resistance test conditions were: 200℃ / 1000 Hr treatment, testing the flexural strength and adhesion strength retention rate; the test results are shown in Table 2.

[0076] Table 2: Performance test results of epoxy resin compositions 1 in various embodiments and comparative examples of the present invention

[0077] Test Project Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Glass transition temperature (°C) 215 212 216 209 168 188 208 Bending strength (MPa) 145 148 146 143 135 140 144 Bond strength at room temperature (kg) 58 65 55 60 35 36 48 Bond strength at 215℃ (Kg) 20 24 16 22 2 6 10 Flexural strength retention rate after high temperature treatment 92% 91% 92% 91% 78% 80% 85% Bond strength retention rate after high temperature treatment 70% 72% 68% 68% 20% 25% 50%

[0078] In Examples 1-4 of this invention, the combination of multifunctional epoxy resin and multifunctional phenolic resin achieves a glass transition temperature that meets the requirements for high-temperature use through high crosslinking density. Furthermore, the use of a special quinoline chelating agent as an adhesion promoter significantly improves the room temperature and high temperature adhesion and its aging thermal stability of the epoxy resin composition 1. In addition, the introduction of an antioxidant greatly improves the stability of the material's mechanical and adhesive properties under long-term high-temperature operating conditions, thus meeting the requirements of long-term high-speed operation of the motor.

[0079] Comparative Example 1:

[0080] Compared with Example 1, the epoxy resin composition for motor rotor encapsulation disclosed in this comparative example contains the following raw materials in parts by weight: 9.25% o-cresol epoxy resin, 3.65% linear phenolic resin, 0.2% accelerator, 0.5% tri-amino-1,2,4-triazole, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives. Other conditions and components are the same as in Example 1.

[0081] As can be seen from Comparative Example 1, the glass transition temperature of epoxy resin and phenolic resin is significantly lower because they are not multifunctional resins.

[0082] Comparative Example 2:

[0083] Compared with Example 1, the epoxy resin composition for motor rotor encapsulation disclosed in this comparative example contains the following raw materials in parts by weight: 8.95% multifunctional epoxy resin, 5.4% linear phenolic resin, 0.2% accelerator, 0.5% tri-amino-1,2,4-triazole, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives. Other conditions and components are the same as in Example 1.

[0084] As can be seen from Comparative Example 2, resin systems with lower glass transition temperatures have poorer high-temperature adhesion; without quinoline chelating agents as adhesion promoters, the adhesion retention rate of the resin composition after thermal aging also decreases significantly.

[0085] Comparative Example 3:

[0086] Compared with Example 1, the epoxy resin composition for motor rotor encapsulation disclosed in this comparative example contains the following raw materials in parts by weight: 9.25% multifunctional epoxy resin, 5.15% multifunctional phenolic resin, 0.15% accelerator, 80% inorganic filler, 0.4% antioxidant, and 4.55% additives, with other conditions and components being the same as in Example 1.

[0087] As can be seen from Comparative Example 3, although the room temperature adhesion is relatively high by adding octa-hydroxyquinoline chelating agents, the high temperature adhesion and the adhesion after heat aging are slightly worse, which also poses a greater risk in the actual long-term high-speed operation of the motor.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An epoxy resin composition for encapsulating an electric motor rotor, characterized in that, It contains the following raw materials by weight: epoxy resin 9.05-20%, phenolic resin 5-20%, accelerator 0.15%-3%, quinoline chelating agent 0.5%-3%, inorganic filler 80%-90%, antioxidant 0.4%-3%, and additives 0.2%-4.55%.

2. The epoxy resin composition for motor rotor encapsulation according to claim 1, characterized in that, The epoxy resin is a multifunctional epoxy resin; the phenolic resin is a multifunctional phenolic resin.

3. The epoxy resin composition for motor rotor encapsulation according to claim 2, characterized in that, The molecular structure of the multifunctional epoxy resin is one or a combination of two of the molecular formulas 1 and 2. Molecular Formula 1: ； Molecular Formula 2: 。 4. The epoxy resin composition for motor rotor encapsulation according to claim 2, characterized in that, The molecular structure of the multifunctional phenolic resin is one or more combinations of molecular formula III, molecular formula IV or molecular formula V. Molecular Formula 3: ； Molecular Formula 4: ； Molecular Formula 5: 。 5. The epoxy resin composition for motor rotor encapsulation according to any one of claims 1-4, characterized in that, The quinoline chelating agent is one or more of amino-substituted quinoline alcohol, carboxyl-substituted quinoline alcohol, hydroxyquinoline ketone, sulfonic acid-substituted quinoline alcohol, and Schiff base quinoline.

6. The epoxy resin composition for motor rotor encapsulation according to claim 5, characterized in that, The quinoline chelating agent is an amino-substituted quinoline alcohol.

7. The epoxy resin composition for motor rotor encapsulation according to any one of claims 1, 2, 3, 4 or 6, characterized in that, The quinoline chelating agent comprises 0.5%-0.8% quinoline chelating agent.

8. The epoxy resin composition for motor rotor encapsulation according to any one of claims 1-4, characterized in that, The accelerator is one or more of organophosphorus compounds, imidazole compounds, tertiary amine compounds, and tertiary amine derivatives.

9. The epoxy resin composition for motor rotor encapsulation according to any one of claims 1-4, characterized in that, The accelerator is one or more of triphenylphosphine, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1,8-diazabicyclo, and undecene-7 (DBU).

10. The epoxy resin composition for motor rotor encapsulation according to any one of claims 1-4, characterized in that, The inorganic filler is one or more of crystalline silica, molten silica, spherical silica, metal oxides, and metal nitrides.

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